Laughs in beam laser.
Feedback cascade could use a tweak to how potent it is, but removing it could result in the return of the Duracell multirole ships and giving it to any weapons with a high ROF would easily result in SCBs being in a worse state than they currently are.
Honestly I think SCBs are a bit OP as-is. The other player should have to seek a moment when they're not taking constant fire in order to trigger them. If that's difficult to achieve, that's a good thing imo. Right now they're too easy to use. I don't think this should be reliant on a specific engineering effect on a specific type of weapon. You could potentially increase the amount of damage needed to cancel them as some compensation.
However, I would keep their breach chance high, but slightly reduce their breach damage and drastically reduce their ability to punch clean through to modules regardless of the impact angle.
Here's my problem with Rails; they're extremely good against shields AND extremely good against hull. Against shields, they're basically superior to laser weapons a grade higher, which is ridiculous. Sure, they generate lots of heat, but that can either be compensated for, OR actively USED to deal MORE damage. They have better DPE, better DPS, better Range. And then, once the shields go down, they're basically better than most kinetic weapons too! They've got better Armor Piercing, better DPS, and insane Breach Damage!
They're clearly excessively powerful. So I tried to think of ways you could nerf them and still keep their relative identity. The thing that makes the most sense to me is that they can't break through armor immediately, but rather need to wear down the target for a bit first. That way, the player is encouraged to have standard kinetic weapons to deal some hull damage first, and THEN they can snipe the power plant and kill the player.
It seemed the best way to preserve the weapon identity while bringing it closer to being balanced.